Ultra high speed direct digital synthesizer using InP DHBT technology

Direct Digital Synthesizers (DDS) offer advantages such as precise beam shaping and forming over conventional RF approaches. This paper discusses novel design and process techniques that enable direct digital synthesis of S-band output frequencies using our current InP double-heterojunction bipolar transistor (DHBT) technology with a cantilevered base layer and undercut collector. The test results demonstrate a DDS chip operating at the world record clock rate of 9.2 GHz. Further design and process improvements will be implemented in future generation circuits that will enable synthesis of Ku-band frequencies.

[1]  T.A. Schaffer,et al.  A 2 GHz 12-bit digital-to-analog converter for direct digital synthesis applications , 1996, GaAs IC Symposium IEEE Gallium Arsenide Integrated Circuit Symposium. 18th Annual Technical Digest 1996.

[2]  E.K.F. Lee,et al.  Design of low-power ROM-less direct digital frequency synthesizer using nonlinear digital-to-analog converter , 1999, IEEE J. Solid State Circuits.

[3]  R. van de Plassche,et al.  A 1 Gs/s, 10b digital-to-analog converter , 1994, Proceedings of IEEE International Solid-State Circuits Conference - ISSCC '94.

[4]  M. Waltari,et al.  A direct digital synthesizer with an on-chip D/A-converter , 1997, Proceedings of the 23rd European Solid-State Circuits Conference.

[5]  H. Samueli,et al.  An 800-MHz quadrature digital synthesizer with ECL-compatible output drivers in 0.8 /spl mu/m CMOS , 1995 .